The International Centre for Settlement of Investment Disputes (ICSID) has become the leading arbitration institution for the resolution of investor-state disputes. Today, any company considering an investment in a foreign country and any financing entity playing a role in the investment must be aware of ICSID and the growing matrix of bilateral investment treaties (BITs) and multilateral treaties (MITs), most notably, the North American Free Trade Agreement (NAFTA) and the Energy Charter Treaty (ECT), providing access to ICSID. Familiarity with the regime and jurisprudence of ICSID arbitration is essential for any international investment lawyer, whether focused on transactions or disputes.